Allow namespace config to be tested properly

Previously, the NewTextContext created a context that always called
NewNameResolver with a export filter that always returned true.

This change fixes that by:
1. Changing NewNameResolver to take a Config parameter instead of a
   filter parameter and pushing the code to create the filter from the
   Config from newNameResolver() in cmd/soong_build/main.go into the
   NewNameResolver function.

2. Extracting a newTestContextForFixture that does not create a
   NameResolver or set it on the context. That avoids creating a
   NameResolver before the test has prepared the config.

3. Modify the fixture to create and set the NameResolver in the Context
   after the config has been prepared by the test.

4. Added test to verify that it all works.

Bug: 234825639
Test: m nothing
Change-Id: Ie4b13f18093dc01a0ab65a9ecfd143585d843b55

android/fixture.go

@@ -658,7 +658,7 @@ func (t *TestPathContext) AddNinjaFileDeps(deps ...string) {
 
 func createFixture(t *testing.T, buildDir string, preparers []*simpleFixturePreparer) Fixture {
 	config := TestConfig(buildDir, nil, "", nil)
-	ctx := NewTestContext(config)
+	ctx := newTestContextForFixture(config)
 	fixture := &fixture{
 		preparers: preparers,
 		t:         t,
@@ -790,6 +790,16 @@ func (f *fixture) RunTest() *TestResult {
 		}
 	}
 
+	// Create and set the Context's NameInterface. It needs to be created here as it depends on the
+	// configuration that has been prepared for this fixture.
+	resolver := NewNameResolver(ctx.config)
+
+	// Set the NameInterface in the main Context.
+	ctx.SetNameInterface(resolver)
+
+	// Set the NameResolver in the TestContext.
+	ctx.NameResolver = resolver
+
 	ctx.Register()
 	var ninjaDeps []string
 	extraNinjaDeps, errs := ctx.ParseBlueprintsFiles("ignored")

android/namespace.go

@@ -91,7 +91,27 @@ type NameResolver struct {
 	namespaceExportFilter func(*Namespace) bool
 }
 
-func NewNameResolver(namespaceExportFilter func(*Namespace) bool) *NameResolver {
+// NameResolverConfig provides the subset of the Config interface needed by the
+// NewNameResolver function.
+type NameResolverConfig interface {
+	// ExportedNamespaces is the list of namespaces that Soong must export to
+	// make.
+	ExportedNamespaces() []string
+}
+
+func NewNameResolver(config NameResolverConfig) *NameResolver {
+	namespacePathsToExport := make(map[string]bool)
+
+	for _, namespaceName := range config.ExportedNamespaces() {
+		namespacePathsToExport[namespaceName] = true
+	}
+
+	namespacePathsToExport["."] = true // always export the root namespace
+
+	namespaceExportFilter := func(namespace *Namespace) bool {
+		return namespacePathsToExport[namespace.Path]
+	}
+
 	r := &NameResolver{
 		namespacesByDir:       sync.Map{},
 		namespaceExportFilter: namespaceExportFilter,

android/namespace_test.go

@@ -602,6 +602,36 @@ func TestRename(t *testing.T) {
 	// RunTest will report any errors
 }
 
+func TestNamespace_Exports(t *testing.T) {
+	result := GroupFixturePreparers(
+		prepareForTestWithNamespace,
+		FixtureModifyProductVariables(func(variables FixtureProductVariables) {
+			variables.NamespacesToExport = []string{"dir1"}
+		}),
+		dirBpToPreparer(map[string]string{
+			"dir1": `
+				soong_namespace {
+				}
+				test_module {
+					name: "a",
+				}
+			`,
+			"dir2": `
+				soong_namespace {
+				}
+				test_module {
+					name: "b",
+				}
+			`,
+		}),
+	).RunTest(t)
+
+	aModule := result.Module("a", "")
+	AssertBoolEquals(t, "a exported", true, aModule.ExportedToMake())
+	bModule := result.Module("b", "")
+	AssertBoolEquals(t, "b not exported", false, bModule.ExportedToMake())
+}
+
 // some utils to support the tests
 
 var prepareForTestWithNamespace = GroupFixturePreparers(

android/testing.go

@@ -30,19 +30,11 @@ import (
 	"github.com/google/blueprint/proptools"
 )
 
-func NewTestContext(config Config) *TestContext {
-	namespaceExportFilter := func(namespace *Namespace) bool {
-		return true
-	}
-
-	nameResolver := NewNameResolver(namespaceExportFilter)
+func newTestContextForFixture(config Config) *TestContext {
 	ctx := &TestContext{
-		Context:      &Context{blueprint.NewContext(), config},
-		NameResolver: nameResolver,
+		Context: &Context{blueprint.NewContext(), config},
 	}
 
-	ctx.SetNameInterface(nameResolver)
-
 	ctx.postDeps = append(ctx.postDeps, registerPathDepsMutator)
 
 	ctx.SetFs(ctx.config.fs)
@@ -53,6 +45,16 @@ func NewTestContext(config Config) *TestContext {
 	return ctx
 }
 
+func NewTestContext(config Config) *TestContext {
+	ctx := newTestContextForFixture(config)
+
+	nameResolver := NewNameResolver(config)
+	ctx.NameResolver = nameResolver
+	ctx.SetNameInterface(nameResolver)
+
+	return ctx
+}
+
 var PrepareForTestWithArchMutator = GroupFixturePreparers(
 	// Configure architecture targets in the fixture config.
 	FixtureModifyConfig(modifyTestConfigToSupportArchMutator),

cmd/soong_build/main.go

@@ -106,19 +106,7 @@ func init() {
 }
 
 func newNameResolver(config android.Config) *android.NameResolver {
-	namespacePathsToExport := make(map[string]bool)
-
-	for _, namespaceName := range config.ExportedNamespaces() {
-		namespacePathsToExport[namespaceName] = true
-	}
-
-	namespacePathsToExport["."] = true // always export the root namespace
-
-	exportFilter := func(namespace *android.Namespace) bool {
-		return namespacePathsToExport[namespace.Path]
-	}
-
-	return android.NewNameResolver(exportFilter)
+	return android.NewNameResolver(config)
 }
 
 func newContext(configuration android.Config) *android.Context {